Improvement in sugar vacuum-pans



J, M. MLLER. VACUUM PAN, GLC.

Patented Oct. 2l, l861 UNITED -STATES PATENT OFFICE.

JAMES M. MILLER. 0F. NEW YORK, N. Y

IMPROVEMENT IN SUGAR VACUUMe-PANS.

Specification forming-part of Letters Pat-ent- No. 8,450, dated October 21, 1851f ments in Vacuun1-Pans and other Sugar-Manufacturing Apparatus., 81e., parts of which are also applicable to other purposes; and I do hereby declare that the following is a full, clear, and exact description of the principle or character which distinguishes them from all other things before known, and of the usual manner of making, modifying, and usi-ng the same, reference being had to the accompanying drawings, of which`A Figure l is a plan of ythe heating-pan; Fig. 2, plan of tubes; Fig. 3, crosssection of boilerpan, 85e.; Fig. 4, longitudinal section of apparatus .for brown sugar; Fig. 5, aview of the apparatus for manufacturing White sugar; Fig. l', a section of the condenser; Fig. 2', a plan of the same; and Fig. '3, a section-.through the boiler, vacuum-pan, condenser, dto.v

My -improvements consist in the mode of constructing steam-pipes for sugar-pans, and in their arrangement and combination with said pans, and with the boiler that supplies them with steam, by which arrangement' the steam is conducted by the shortest possible course through pipes to every part of the pan,

and the condenser steam or Water has a free and direct course back into the boiler.

I am aware that large pipes have been eml ployed for evaporation in pans, and also that the waste condensed steam has been made to run'back through the same pipeinto the boiler. Consequently these abstract ideas are not designed to vbe covered by me in this invention; but in all the attempts of this kind with which I am acquainted a failure has ensued on ac,

count of the improper construction of the apparatus, as neither a coil or 'Worm will answer, the distance which the steam has to trav-` erse being too great, and consequently the 'current through them too strong. This effect I have found in actual practice to be the case, and that the length of tubes or distance from the farthest extremity to the boiler cannot be indefinitely increased Without spoiling the effect. There are many other defects, which I will not now enumerate, in. inventions of this class hitherto made. I have, after much labor and expense, at last succeeded in constructing an apparatus .that will work, and which produc-csa much greater el'iect than any other with which I am acquainted, While the apparatus is in uch less liable to injury by expan- Sion and contraction oi' the tubes, which in this may be ever so unequal and ever so rapid Withoutanystrain 011 the parts. The steam is admitted at the center, and none ofthe pipes are'attach'ed to any non-yielding fixture, by which they can be strained. This is of utmost importance in practice. There are two other dessential points neecssaryto be understood before my improvements can be fully appreciated. First, the pipes must be madeof as large diameter as is consistent with the inanimum thickness of metal to obtain the best circulation, uhielrdiaineters I have' found by careful experiment to be about four inches for the branch tubes and about six inches for the main tube, the metal which I have foundbest adapted I ment is notA unlike-that is, av series of short pipes branching from a main. The outer ends of the lateral vpipes are a little elevated to insure the discharge of anyl condensed steam Withinytl'ieni into the`niaiu pipe, which thence finds its way into the boiler, and is reconverted into'steam of high temperature, to again con- Vey its-heat to the surrounding medium. The center main, s, is connected at its center (or if very long i 11 two or more places) with the boiler by short vertical pipes a. The boilers 'are of any ordinary construction, and are furnished with a common safety-valve, B. As there is no escape-steam unless the reis forced so hard as to cause the safety-valve to rise, it is obvious that no supply of Water will be required, and to supply this occasional Waste Very little will suiiice. The vertical pipes a descend into the top of the boiler, which is located directly under` the pans for that purpose. Each of these pipes is tted 'with a valve or' stop-cock, c, for regulating the admission of steam into the tubes s in the -pan above.

The'pans E areinadc in the usual. way, and may be mmh, either square, as shown in the/ of' brown sugar, are madeof any ordinary shape, and placed in a range, all on alevel, or nearly so, instead of' being one above another, as in the ordinary ranges now in use. These pans are connected at the bottom by openings,

' which are closed by sliding gates, one of which.

is shown at y, Fig. 3, in dotted lines. It is raised by the lever-handle N.l Each of the partitions between the pans after the first is made lower than the preceding one, and the bottoms of all except the first pan are covered with rows of pipes. The first pan has about one-third of' its space (next the precipitation) without any pipes in it, which leaves a space for the scum to eddy back into, the course of the scum being backward toward said space from which it is removed.

There is a heating-pan, K, above the series before named, iu which I have a series of pipes formed like those Vin the pans below. These pipes receive the exhaust-steam from the steam-engine, and serve the double purpose of creating a partial vacuum and of heating the cane-juice to a boiling-point directly after it leaves the mill. An inverted-Siphonshaped tube, O, connect-s with those tubes from below, as shown in Fig. 4, in which there is a common cheek-valve at I?, the case only of which is shown in the-drawings. From this the pipe It connects with the air-pump. Besides this, there is another branch 'on one side, in which is placed a second check-valve, Q, communicating with an escape-pipe, so that if the steam is not all condensed in the tubes or pumped out it 'may escape through this passage, which is at the same time guarded against the admission of` air by the valve Q, which would otherwise be very injurious'in operations of this kind. The precipitator L is a little below the heater K, and receives the cane-juice from it in a heated state, when it has time' to settle, there being no heat applied in this pan,and as the j uiceis thencedischarged into the first pan, E, in the train below through a spout, where the boiling first commences by letting in the steam upon the section of pipes connected therewith. Vhen the second pan'is to be charged, the handle N of the gate g in the partition between it and the first pan is raised, and the contents are transferred, the first pan rccei ving a second charge from theheating-pan above. From the second to the third pan the same method is pursued, and so on to the fourth, where the operation is completed: If it is found in practice that one set of vpipes do not evaporate fast enough for thepurpses required, two or more may be employed, one being placed over another. i'

It is obvious that the pipes` may be used for pausionsv and contractions were 1 straining all its joints; but in `my c4 various other purposes as well as for sugarmaking-such as all other evaporating processes, distilliug, the.; and they may be employed 'in rucuo or otherwise, as is deemed adi visable. Y

For the apparatus for evaporating 'in vacuo for white sugar I employ two (more or less) filters, through'which the cane-juice passes from the precipitator that is placed above said filters. The filters are upright cylinders placed somewhat below the vacuum-pans,with which they are combined, so that the vacuumpan shall perform the ofiiee of creating vacuum in the filter'and also boil in vacuo. These filters receive the cane-juice at their lower ends. The first, O, receives the Juice from f the prceipitator through 'a long descending pipe, T, regulated by astop-l cock, l. The lower part of this filter, up tothe dotted line X, servesas a pr'ccipitator. From this line to W theispace is filled with the filtering medium', through which the cane-juice is filtered upward, and descends through a second pipe,

in which is a stop-cock, 2, to the bottom of' l the second filter, O', where it again ascends through the filtering medium from X to XV,

and thence enters through'stop-cocks 3 and 4.

to the vacuum-pans l`through pipes .I and V, the juice being drawn up by the vacuum in the pau. The filters are cleaned by admitting steam at'the top, and thus forcing the impurities down through the filtering medium.` In the vacuum-pans are placed series of pipes, as in the open pans above described, as shown in section, Fig. 1. On the top of the vacuumlpans are domes, f'rom the top of which are pipes conducting to the condenser D. (Shown also in'seetion in Figs.' l', 2', and 3'.) In the tubular condeusers that have generally been used the shell of the condenser necessarily had to sustain the pressure of the atmosphere caused by the vacuum.` This on aV large sur- `face was very great, requri'ngthe shelljfto be made very stout and well braced, an l-gzexessarily 931.501 the whole system works from a center asabase or fixture, allowing al1 its arms or radii to expand and contract in any manner withoutinjury to their joints. The horizontal pipes eX tending from the main nearly to the case have within them smaller pipes, that are attached all round to the edge of their outer ends', as clearly shown in theenlarged view at Fig. l',

the outer pipes being open at-the end and the inner one having a convex end piece at its inner end. The pipethus constructed is as if one half of it was turned back wit-hin the other and reversed, forming al1-annular space between the two halves for the steam to ent-er, the body of the cold water surrounding it on the outside, and also on the inside.

Having thus fully described my improved apparatus and its purposes, I claim'as my in. vention and desire to secure by Letters Patent-'. I. rIhe evaporating anu condensing tubes constructed and arranged in the manner and for the purpose set forth, they being attached at one point 0nlythrough which the steam enters, having freedom to expand or contract without injury, and the evaporatingtnbes being` combined at the center-of the series.v as above specially set forth, with the boiler, the steam is conveyed from the boiler to the extremities of all the tubes in the most direct manner.

' 2. Connecting the filters with the Vacuumpan `in the manner and for the purpose setv -oondenseitnbes above specified, the ends of said tubes being,r turned back inwardly nearl)Y the whole length of the outer portion, as distinctly shown in the drawings.

J. M. MILLER. Witnesses:

EDWARD EYERETT, WM. GREENOUGIL 

